The Forbidden Cities are what the Elves call human territory. All of the world we know is part of the Forbidden Cities.
Forbidden Cities Visited in The Keeper of the Lost Cities Series Edit
San Diego, California Edit
Hollywood, Los Angeles, California Edit
Gryfino, Poland (The Crooked Forest) Edit
California's White Mountains Edit
Paris, France Edit
Mt. Everest Edit
The Himalayas Edit
-Visited by anyone who has gone to the Sanctuary.
Florence, Italy Edit
-Visited by Sophie, Fitz, Keefe, Dex, Biana, Della, Mr. Forkle, possibly other members of the Black Swan, and at least one Pyrokinetic in the Neverseen, including Brant or Fintan. Most likely Brant, as Fintan usually stays where it's safe.